Fixed: allow omitting the current version in sample-config

If the current version is explicitly left empty during the
`sample-config` questionnaire, the resulting `tool.bumpversion` table
now lacks a `current_version` key, and will fall back to PEP 621
`project.version` (if not dynamic). The instruction text specifically
hints at this new functionality.

Author: the-13th-letter

bumpversion/config/create.py

@@ -23,7 +23,14 @@ def create_configuration(destination: str, prompt: bool) -> TOMLDocument:
     if prompt:
         allow_dirty_default = "(Y/n)" if config["allow_dirty"] else "(y/N)"
         answers = questionary.form(
-            current_version=questionary.text("What is the current version?", default=config["current_version"]),
+            current_version=questionary.text(
+                "What is the current version?",
+                default=config["current_version"],
+                instruction=(
+                    "If omitted, use the project.version key in pyproject.toml. "
+                    "(Does not support dynamically set versions.)"
+                ),
+            ),
             commit=questionary.confirm(
                 "Commit changes made when bumping to version control?", default=config["commit"]
             ),
@@ -45,6 +52,8 @@ def create_configuration(destination: str, prompt: bool) -> TOMLDocument:
         config.update(answers)
 
     for key, val in config.items():
+        if key == "current_version" and not val:
+            continue
         destination_config["tool"]["bumpversion"][key] = val if val is not None else ""
 
     return destination_config

tests/test_config/test_create.py

@@ -166,3 +166,20 @@ def test_prompt_true_asks_questions_and_updates_result(self, tmp_path: Path, def
         assert destination_config["tool"]["bumpversion"]["tag_message"] == default_config["tag_message"]
         assert destination_config["tool"]["bumpversion"]["tag_name"] == default_config["tag_name"]
         assert mocked_questionary.form.return_value.ask.call_count == 1
+
+    def test_prompt_true_empty_current_version_removes_key(self, tmp_path: Path, default_config: dict, mocker):
+        """If prompt is True and if current_version is empty, that key should be missing in the answer."""
+        answer = {
+            "current_version": "",
+            "commit": True,
+            "allow_dirty": True,
+            "tag": True,
+            "commit_args": "--no-verify",
+        }
+        mocked_questionary = mocker.patch("bumpversion.config.create.questionary", autospec=True)
+        mocked_questionary.form.return_value.ask.return_value = answer
+        with inside_dir(tmp_path):
+            destination_config = create_configuration("pyproject.toml", prompt=True)
+
+        assert "current_version" not in destination_config["tool"]["bumpversion"]
+        assert mocked_questionary.form.return_value.ask.call_count == 1